It is known in the art to record latent image data on photographic film in association with exposed, latent image picture frames. Such data can include, for example, time/date information which is subsequently developed with the latent image and printed on the final print.
It is further known in the art to record latent image data which can be used in printing developed negative frames. U.S. Pat. No. 4,493,547 to Bridges (assigned to the assignee of the present invention), for example, shows apparatus for recording a vertical/horizontal camera orientation on the film in association with each picture frame. Such information can be used, for example, during the printing process to aid in identifying a main subject and calculating an appropriate color printing exposure.
U.S. Pat. No. 4,079,388 to Takahama et al. shows apparatus for use in a camera which functions to distinguish between natural daylight, fluorescent light, and tungsten light in a picture scene. The apparatus further functions to mark the film with a latent image identifying the light type. During printing, the exposed marks on the film are read to determine the type of light present in each negative frame. This information is used in calculating appropriate printing exposures for the negative frames.
Many printers in use today operate automatically, i.e. without human intervention, to calculate an appropriate printing exposure for each individual negative frame. These printers typically scan each negative frame to measure color densities, and, based on pre-programmed algorithms, identify a primary subject, classify the negative frame as a particular type (i.e. back-lit), or make some similar decision regarding the negative frame content. Based on this decision or decisions, an appropriate printing exposure is calculated.
One disadvantage in the printing operation described above is that, operating without human intervention, photographic printers can be "fooled" into making improper decisions regarding negative frames. Improperly identifying a subject, misclassifying a negative type, or otherwise making an error in examining a negative frame often results in the calculation of an improper printing exposure.